Incandescent lamp



March 26, 1968 R. G. MORGAN INCANDESCENT LAMP Filed Oct. 22, 1963 ROBERT s. MORGAN I N VEN TOR.

ATTOR EY United States Patent Office 3,375,393 INCANDESCENT LAMP Robert G. Morgan, Ipswich, Mass, assignor to Sylvania Electric Products Inc., a corporation of Delaware Filed Oct. 22, 1963, Ser. No. 317,921 2 Claims. (Cl. 313-269) This invention relates to electric lamps and more particularly to incandescent electric lamps of the miniature type.

In recent years great advances have been made in the development of many kinds and types of electrical and electronic equipment. This, in turn, has resulted in a large number and a great variety of applications for miniature light sources, such as the so-called indicator and pilot lamps for example. In some of these applications, particularly military uses, space is at a premium and normally encountered operating conditions are quite severe. When space is at a premium, simplicity of structure normally suggests itself. On the other hand, if extreme conditions of mechanical shock and vibration must be reckoned with, a more complex structure would appear to be necessary.

In view of the foregoing, the principal object of this invention is to provide a miniature incandescent light source which is small, compact, simple in structure and yet rugged and durable enough to withstand extreme conditions of mechanical shock and vibration.

This and other objects, advantages and features are attained, in accordance with the principles of this invention, by using a stem type mount in a tubular lamp envelope, with the filament support wires frictionally engaging the inner wall of the lamp envelope.

In the accompanying drawing illustrating a specific embodiment of the invention, FIGURE 1 is a side elevational view of an incandescent lamp.

FIGURE 2 is a front elevational view of the lamp of FIGURE 1.

FIGURE 3 is a traverse sectional View taken along the line 3-3 of FIGURE 1.

The lamp illustrated in the accompanying drawing comprises a substantially tubular glass lamp envelope 1 and a stem 3 disposed within and hermetically sealed to one end thereof. The lamp is provided with a base contact assembly comprising a wedge-like base 5 of suitable insulating material and a pair of metal clips 7. Each of the metal clips 7 is secured at one end thereof in the wedge-like base 5. The metal clips 7 are preferably shaped somewhat to the contour of the lamp envelope along which they extend. The segments of lead-in wires 9 and 11 which lie outside of the stem 3 are folded back along the sides of the lamp envelope 1 and are secured to the metal clips 7 by a suitable conducting cement. Thus the metal clips 7 define base electrical contacts for the lamp.

The mount structure of the specific embodiment of the invention comprises a pair of lead-in wires 9 and 11 sealed in and extending through the stem 3, a filament 15 and a plurality of filament support wires 17, 19 and 21. One end of each of the filament support wires is embedded in the stem 3 and the other end of each is looped around the filament 15. The filament 15 is secured at its ends to lead-in wires 9 and 11 and extends through and is supported by loops 17a, 19a and 21a of filament support wires 17, 19 and 21 respectively. The filament support wires 17, 19 and 21 are somewhat 3,375,393 Patented Mar. 26, 1968 arcuate in contour and frictionally engage the inner wall of the lamp envelope 1 intermediate the ends thereof. Thus when the lamp of this invention is subjected to severe mechanical shock and/or vibration, far in excess of what conventional lamps can withstand, the resilient filament support wires bearing against the inner Wall of the lamp envelope will absorb the greater portion of the shock and thus minimize the transmission of these forces to the filament. Thus a lamp having a mount construction of the type just described may be safely and reliably employed in applications where severe mechanical shock and/or vibration can be expected under certain environmental conditions without the danger of lamp failure at critical times.

What I claim is:

1. An incandescent electric lamp comprising: a substantially tubular glass envelope; a lamp stem disposed within and hermetically sealed in said envelope at one end thereof; a pair of lead-in wires sealed in said stem and extending therethrough; a lamp filament, the ends of which are secured to the inner ends of said lead-in wires; and a plurality of filament support wires, one end of each of which being anchored in said stem, the other end of each of which being looped about said lamp filament intermediate the end thereof, and each of said filament support wires frictionally engaging the inner wall of said envelope intermediate the ends thereof.

2. An incandescent electric lamp comprising: a substantially tubular glass envelope; a lamp stem disposed within and hermetically sealed in said envelope at one end thereof; a pair of lead-in wires sealed in said stem and extending therethrough; a lamp filament, the ends of which are secured to the inner ends of said lead-in wires, a plurality of filament support wires, one end of each of which being anchored in said stem, the other end of each of which being looped about said lamp filament intermediate the ends thereof, and each of said filament support wires frictionally engaging the inner wall of said envelope intermediate the ends thereof; and a base-contact assembly secured to said envelope at the stem end thereof said assembly comprising a wedge-like member of insulating material and a pair of metal clips supported in said wedge-like member of insulating material, the outer ends of said lead-in wires being connected to said metal clips.

References Cited UNITED STATES PATENTS 669,306 3/1901 Howell 313-318 898,752 9/1908 Kuzel 313-274 X 1,046,677 12/1912 Tate 313-269 X 1,075,475 10/1913 Henderson 313-269 1,720,311 7/1929 Becket 313-274 X 1,869,998 8/1932 Cartun 313-274 1,983,362 12/1934 Geiger et al. 313- 2,225,090 12/ 1940 Wiener 313-271 2,278,816 4/1942 Zabel 313-277 X 2,886,735 5/1959 Anderson 313-274 3,036,236 5/1962 Meyer 313-318 3,069,583 12/1962 Swasen et al 313-317 3,223,875 12/1965 Eggers 313-271 JOHN W. HUCKERT, Primary Examiner. A. 1. JAMES, Assistant Examiner. 

2. AN INCANDESCENT ELECTRIC LAMP COMPRISING: A SUBSTANTIALLY TUBULAR GLASS ENVELOPE; A LAMP STEM DISPOSED WITHIN AND HERMETICALLY SEALED IN SAID ENVELOPE AT ONE END THEREOF; A PAIR OF LEAD-IN WIRES SEALED IN SAID STEM AND EXTENDING THERETHROUGH; A LAMP FILAMENT, THE ENDS OF WHICH ARE SECURED TO THE INNER ENDS OF SAID LEAD-IN WIRES, A PLURALITY OF FILAMENT SUPPORT WIRES, ONE END OF EACH OF WHICH BEING ANCHORED IN SAID STEM, THE OTHER END OF EACH OF WHICH BEING LOOPED ABOUT SAID LAMP FILAMENT INTERMEDIATE THE ENDS THEREOF, AND EACH OF SAID FILEMANT SUPPORT WIRES FRICTIONALLY ENGAGING THE INNER WALL OF SAID ENVELOPE INTERMEDIATE THE ENDS THEREOF; AND A BASE-CONTACT ASSEMBLY SECURED TO SAID ENVELOPE AT THE STEM END THEREOF SAID ASSEMBLY COMPRISING A WEDGE-LIKE MEMBER OF INSULATING MATERIAL AND A PAIR OF METAL CLIPS SUPPORTED IN SAID WEDGE-LIKE MEMBER OF INSULATING MATERIAL, THE OUTER ENDS OF SAID LEAD-IN WIRES BEING CONNECTED TO SAID METAL CLIPS. 